1. Field of the Invention
The present invention relates generally to robotic assemblies operable to move a platform up and down along a Z-axis via a cable assembly to manipulate media elements within a storage library and, more particularly, to devices and methods that serve to selectively lock a drive assembly, such as during shipping or the like, against movement that would otherwise allow for back driving of the cable assembly and inadvertent dropping of the platform, all of which could lead to damage to the cable assembly and/or other components of the robotic assembly.
2. Relevant Background
Storage library systems are often used by enterprises and the like to efficiently store and retrieve data from storage media. In the case of some storage libraries, the media may be data cartridges (e.g., tape cartridges) that are typically stored and indexed within a set of magazines. When particular data is requested, for instance, a specialized robotic assembly or mechanism (e.g., robotic module) finds the appropriate cartridge, removes the cartridge from its magazine, and carries the cartridge to a drive that is designed to receive the cartridge and read its contents. Some storage libraries have multiple drives that can operate concurrently to perform input/output (IO) operations on multiple cartridges.
To operate properly, the robotic mechanisms are expected to reliably (e.g., repeatably and accurately) and rapidly find, retrieve, and deliver desired cartridges throughout the storage library cartridge inventory. Generally, a robotic mechanism may include a hand assembly that is operable to reliably grip a desired cartridge and remove it from a magazine or drive, or to reliably grip a cartridge and release the cartridge into a desired magazine slot or drive. The robotic mechanism may be configured to move the hand assembly in one or more axes (e.g., x, y, and Z-directions, and sometimes one or more of pitch, roll, or yaw), and may include one or more sensors to reliably detect the position and/or orientation of the hand assembly.
Different implementations of storage library systems move the hand assembly in the Z-direction (i.e., with and against the force of gravity, such as vertically with respect to the cartridge inventory) in different ways. Some implementations may use gears, tracks, belts, hydraulics, and/or other such control mechanisms. Other implementations associate the hand assembly with a platform or carriage that is held up by cables, ropes, or the like. By pulling on the cables (e.g. using pulleys, a spool, a drive motor, etc.), the platform or carriage can be lifted; by adding slack to the cables, the platform or carriage can be allowed to move in a downward direction under the force of gravity (e.g., in a substantially floating manner).